A desired material to be plated is deposited on the surface of an object positioned at a negative electrode by using electroplating utilizing the principle of electrolysis. Basic elements for the electroplating include a positive electrode, a negative electrode and an electrolyte. In addition, the electrolyte includes a metal material or ions of the metal to be plated.
During the electroplating, deposit stress may be generated at a plated film. The deposit stress includes a compressive stress and a tensile stress. These stresses induce various limitations. These limitations include the adhesion of an electroplated film and a base material, the breaking phenomenon due to the deformation of the base material, the difficulty of assembling during conducting an assembling process of a plated base material, the deterioration of the reliability of a product, the decrease of the lifetime of a product and the like. Particularly, the limitations due to the deposit stress may be generated more significantly in a product in which the plating is conducted only on one side thereof when compared to a product plated on both sides thereof.
For example, when manufacturing an electrode for a touch screen of which use is increasing due to the explosive increase of smart devices in these days, if employing an electroplating method instead of a screen printing method or a sputtering method, only one side is usually plated. In addition, when manufacturing an electrode used in a solar cell which is one of clean energy sources by the electroplating method instead of the common screen printing method, only one side is usually plated. The one-side plating causes the base material of a product manufactured by the electroplating to be deformed, or the adhesive strength of the base material such as a silicon wafer, reinforced glass or a plastic resin with a plated film to be deteriorated due to the above-described deposit stress.
If the electrode of the solar cell or the electrode of the panel of the touch screen is manufactured by applying the electroplating method, the price competitiveness is improved as compared to other plating methods. However, despite the price competitiveness, since the electroplating method causes technical disadvantages as described above, the electroplating method has not been actually utilized.
Accordingly, if the deposit stress generated in the electroplated copper film could be relieved, a copper electroplating method could be applied, and thus, production costs may be largely reduced. Particularly, economic feasibility is even more significant when considering the steep increase of the production costs due to the price rise of a silver paste, etc. that are currently used as the electrode.
The present technology described in this patent document is a result of the research efforts by the inventors and can be used to address the above-described limitations.